A valve with a movable control spool is disclosed in the data sheet which has been able to be downloaded since Feb. 6, 2016 using the internet link http://www.boschrexroth.com/various/utilities/mediadirectory/download/index.jsp?object_nr=R E64322. The position of the control spool is adjusted as a result of pressure being applied to two control spaces. Air, which disturbs the adjusting of the control spool, is able to accumulate in said control spaces as, unlike hydraulic oil, it is compressible. Vent screws, by way of which the air is able to be removed from the relevant control space, are consequently provided on the corresponding control covers.